1. Southway Animal Clinic and Hospital, 705 16th Avenue, Lewiston, Idaho 83501, USA
2. Idaho Fish and Game Department, 109 West 44th Street, Boise, Idaho 83604, USA
3. U.S. Department of Health, Education, and Welfare, Public Health Service, National Institutes of Health, National Institute of Allergy and Infectious Diseases, Epidemiology Branch, Rocky Mountain Laboratories, Hamilton, Montana 59840, USA
4. Animal Disease Research Unit, U.S. Department of Agriculture, SEA-Western Region, Washington State University, Pullman, Washington 99164, USA